Machine for making composite sheets



2 Sheets-Sheet 1 Wm. .H ...N .m

H. W. COOPER MACHINE FOR MAKIN COMPOSITE SHEETS Original Filed Nov. a,192':

Nov. 3, 1931.

. V J l U Nov. 3, 1931 H. W. COOPER MACHINE FOR MAKIN COMPOSITE SHEETSOriginal Filed Nov. 5,

2 sheets-sheet 2 i In ve 27101 Patented Nov. 3, 1931 UNITED STATES PATNi o -icr.

HENRY W. COOPER, OF WEST NEWTON, MASSACHUSETTS, ASSIGNOR T NEW ENGLANDMICA 00., OF WALTHAM, MASSACHUSETTS, A CCRPOIEi-Ia'JJIOIZl' OFMASSACHUSETTS MACHINE FOR MAKING COMPOSITE SHEETS v Original applicationfiled November 3,

The present invention relates tomachin'es' in the application filed byme November 3,

1927, Serial No. 230,892,.from which this application is a division, acomposite sheet is formed by assembling its component parts, the micaflakes, in a dry condition, and then the complete loose assembly of therequired thickness is drenched with an adhesive while the componentparts of the assembled sheet are retained against displacement.

The principal object of the present inven tion is to produce a machinefor practising the steps of my novel method. I

To the accomplishment of this object a feature of the present inventioncontemplates the provision, in a machine for making composite micasheets, of means for forming a. complete, preferably dry, loose assemblyof mica flakes to the required thickness, means for drenching theassembly with an adhesive and means for retaining the component parts ofthe assembled sheet from displacement while it is being drenched. 1

Broadly considered the means for forming a complete loose assembly ofthe component parts to the required thickness, the means for drenchingthe assembly with an adhesive,

and the means for retaining the component parts of the assembled sheetfrom displacement while it is being drenched'may take any selected form.It is preferred, however, to form the complete, loose assembly of micaflakes to the required thickness by showering the flakes in layers upona movable surface, such as a conveyor, to drench the assembly with anadhesive by dipping the conveyor with the assembly offiakes thereon in abath of liquid adhesive, and to retain the assembly from displacementduring dipping by an apron'which covers the assembly and presses ityieldingly against the conveyor. The term dipping is used herein toinclude the immersion of the assembled sheet in the bath of adhesive andthe with-' drawal of the assembled sheet therefrom.

1927, Serial no. 230,892. Divided and'this application filed August 15,1929.' Serial No. 386,052. w Y

During that part of the operation 0f the? I dipping means in which theassembly of flakes is withdrawn from the bath of liquid adhesive andwhile the component parts of the assembly are held from displacement,the

machine preferably is provided also with means forfsubjecting theadhesive-perme ated assembly of mica flakes to a solidifying pressure toform it into an integral sheet.

Further features of the present invention arr. ngements of parts tendingto improve and simplify the operation of machines for making compositesheets and enable them to operate with certainty and without liabilityof breakage of. parts. The advantage of these devices, combinations andarrangements of parts will be obvious to those skilled in. the artffromthe following description.

The various features of the present invention' will be readilyunderstood from an inspection ofthe accompanyingdrawings illustratingthe best form of the invention at" agrammatically the entire machine upto the inspection table.' p v v In the illustrated embodiment of thein-.

vvention the machinefor making composite mica sheets comprises anelongated frame upon which the successively "operating mechanisms'areassembled. These comprise an endless conveyor extending the full lengthof the frame. bins and sifting mechanism located at one end'of the frameforshowering successive layers of mica flakes upon the conveyor While itis travelling beneath the bins, mechanism for dipping the conveyor.together with the mica flakes thereon into the machine illustrated c wCOIlSlSb'lH certaln devices, combinatlons and a tank of liquid adhesive,mechanism for permeated layers of mica flakes into an integral sheet,and an apron, which is applied to the micafflakes on the conveyor beforethe dipping operation and which is removed from the mica flakes afterthe compressing and compacting operatiomfor retaining the dry micaflakes from displacement on the conveyor while the assembly is beingdipped and compacted. o. V

The main frame of the machine, of considerable length, is built up ofpairs of angle iron posts or legs 5 (Fig. 1) connected by cross bars,notshowmand by long horizontal side bars 6. The conveyor 7 is made up ofa pairof spaced sprocket chains'to which are connected the edgesof a webof toraminous material, preierably a wi'remesh cloth 8 having about fourmeshes to the inch. Thev chains of the conveyor 7 are supportedanddriven by a'series of sprocket wheels 9 (Fig. 1)ca'rriedby transverseshafts 10 journaled in the main frame of the machine and each carrying aworm wheel 11, meshing with a worm 12 mountednpon a shaft 13 extendinglongitudinally for 'the whole length of the frame and journaled in boxes14 carried by the legs 5 thereof. The shaft 13 is driven-from anyconvenient source'of power. not shown, and acts to.

drive all of the sprocket wheels 9 in a counter clockwise direction, soas to advance the upper pass of the conveyor 7 from right to 'left, asseen in the drawings. lhe lower pass of the conveyor is supported byidle rolls 15 journaled between each. pair 1egs5."

At the'right-h'and end of thefram'e above the. conveyor is located anumber of bins 16, two of which only are'shown n Fig. 4. Each of thebins contains t'wooscil lati ng cradles 17 with perforatedwalls ofexpanded metal, having openings of appropriate dimensions and adapted 1nthe r oscillation to sift out and shower mica flakes upon the conveyorpassing beneaththem;

The flakes are supplied in bulk to these cradles through suitable ducts'18 extending into the bins 16 from a source of supply, not shown. Eachof the cradles is carried by a transverse shaft 19, having a toothedsegment 20 at one end, meshing with a horizontally disposedreciprocating. rack 21 guided by spaced pairs of rollers 22 and actuatedfronr a crank disk 23 through a connecting rod 24.] The crank disk iscar ried by a transverse shaft 25', driven by a belt 26 from a motor 27or other convenient source'of power. Clutch mechanism, controlled by ahandle 28 (F ig. 4:) is provided for throwing each cradle into or out ofoperation in accordance withthe requirements ofthe work in hand." g Themechanism above d'escrlbed 1s indiing the flakes to out of the lowerlayer of the flakes, so that only flakes larger than the mesh of theconveyor are carried away from'the-first bin;' The number of the cradlesand their rate of supply is so controlled that the layer of flakes, asit passes from the left-hand bin of the series, is built up to therequired thickness and constitutes a loose, dry assembly of materialjust prior'tothe operation of bind produce an integral'coinpo'sitc micasheet; j"

Figs. 1,2 and .3 illustrate in: somewhat greater structural detail thatportion of the machine wherein adhesive is supplied tot-he layer offlakes assembled'on'the conveyor in the manner above set forth. The mainframe of the machine carries an elongated tank 29, located to the leftof 'the'last bin 16 of the series and in such position thatthe conveyor7 can be deflected into the adhesive" which the tank contains, thisconveniently being shellac. To this end, guiderollers 30 are providedwhich lead the conveyor 7 to the wall of the tank 29, then deflect itdownward ly below the surface of the shellac and finally guide it backint-o its original path as it leaves the tank. The rollers 30 arejournaled'in the side bars 6 and are provided with sprocket wheelsat'ejach end which -111e Sl1 with the chainsof the conveyor 7 so thatthe rollers are drivenfat the same surface speed as the conveyor.- 9 5 Ip In order to prevent displacement orfloati'ng away of the mica flakesas theseare carried into the shellac by the conveyor 7, provision ismadefor engaging the'to'p layer of "the showered flakes thus holding'allthe layersin place upon the web 8 ofthe conveyor: This is effected by anendlessapron of wire mesh cloth 31, which is guided into' engagementwith thesur'fac'e layer of mica flakes on the web 8 as the latter entersthe t ank 29. For this purpose, a series of three drums32, 33 and 3tisprovided for driving and guiding the apron 31 in the desired'p'at-h. 7T'hedrum 32'is carried by a transverse-shaft 35, jour naled in suitableshaft hangers 36 (Figs. and 3)bolted to the side rails 6 of the frameand carrying sprocket-wheels 87 at its outer ends which mesh with andare driven by the int apron 31 into contact with the conveyor,automatically and progressively covering the loose assembly offlakesthereon.

The center drum 33 is an idle roll and is constructed and arranged tomaintain suitable yielding tension upon theapron 31. To

this end, it is journaled in sliding boxes 41 (Fig. 1) mounted forvertical movement in slotted hangers 42, secured to the rail 6, andhaving its weight compensated to some extent by compression springs 43disposed beneath the boxes. I

The apron 31 is maintained in contact with the conveyor 7 throughout thecourse of its travel in the shellac bath and until after it has emergedtherefrom. The roller 30, located at the left end of the tank 29,cooperates with a presser roller 44 for pressing, compacting andsolidifying the sheets of cohered layers of mica flakes as it iscarriedout of the shellac bath between the conveyor 7 and the apron 31 andthese rolls also serve for stripping surplus shellac-from the sheet,

so that it may be returned to the tank. The

roller 44 is carried by a shaft 45 journaled in boxes 46 mounted in apair of slotted hangers 47, secured to the side rails 6 of the frame.Each box is urged upwardly by compression spring 48 located beneath itbut may be moved downwardly to exert a predetermined but controllableamount of pressure upon the layer of mica by a handscrew 49 provided forthat purpose.

As the solidified and now unified composite mica sheet is carried beyondthe drum 32, the apron 31 is stripped from it and the sheet is carriedforward, exposed upon the conveyor 7 where it may be convenientlyinspected and eventually cut into smaller sheets of commercial sizes.

In my co-pending application Serial No. 230,891 filed of even date withthe parent case of which this application is a division I have shown acomplete mica plate laying machine, including a light table forinspection and rectification of the sheet, of the same general design asis partially illustrated by Fig. 4 of this application but difleringtherefrom in that means is provided for applying adhesive binder to eachlayer of the mica flakes as they are successively showered upon theconveyor. The herein illustrated mechanisms may be substituted in themachine of my co-pending application for the mechanisms employed foreffecting said step-by-step application of the binder with a saving ofthe binder and an increased dielectric strength in the finished plate.Accordingly generic claims to the complete machine and method ofmanufacture will be found in my co-pending application Serial No.230,891, the claims of this application being confined to thealternative mecha nism for supplying the binder.

The nature and scope of the invention having been indicated and itspreferred embodiment having been specifically described, whatis claimedas new, is

1 -1. A machine for making endless sheets of I above the tank supportedand guided to cause its lower pass to engage the mica flakes onthat'portion of theupper pass of the conveyer that is travelling throughthe adhesiv'efand drivingmean's'for the covering apron actuated byengagement with the conveyer thus continuously to maintain. uniformityof advance throughout their com-f bined travel through the tank and tohold the component parts of the loose mica flake assembly fromdisplacement.

2. A machine for making endless sheets of composite mica according toclaim 1 having a sprocket chain at each edge of the con veyer, sprocketsengaging in said chains to advance the conveyer, rotary drums forsupporting and guiding the covering apron, and sprocketson said drums ofthe same size as the first named sprockets also engaging in said chainswhereby the covering apron is advanced at the precise rate of speed ofthe conveyer.

3. A machine for making endless sheets of composite mica having, incombination, an endless conveyer having the greater portion of its upperpass guided in a definite path, means for advancing said conveyer, meansat separated stations for showering successive layers of dry mica flakesupon said moving upper pass to build up a loose dry assembly of thedesired thickness, a tank of liquid adhesive relatively short ascompared to the length of the conveyer and disposed intermediate itsends, means for deflecting the conveyer with its loose assembly of micaflakes out of its path and into the adhesive and then to pass onward,and a. moving covering apron acting to engage the assembly of flakes andhold them against displacement while being dipped and then disengagefrom the cohered, flakes as the conveyer carries the unified compositemica, sheet onward.

v 4. A machine for making endless sheets of composite mica having, incombination, a conveyer for a loose, dry assembly ofmica flakes, a tankof liquid adhesive, an endless apron over the tank, common means fordeflecting the upper pass of the conveyer and the lower pass of theapron into the adhesive permitting the adhesive to permeate thetheretofore dry assembly of flakes held there- I between, and means formaintaining a yield ing tension on. the apron by Weighting its upperpass.

5. A machine for making endless sheets of I composite micav having, incombination, a long endless conveyer, means for depositing an assemblyof dry mica flakes thereon, a short endless covering apronlocatedintermediate the ends of the conveyor, driving mechanism for theconveyer, including sprockets at each side thereof, driving mechanismfor the apron including sprockets of the same size at each side thereof,saiddriv- 111g mechanism including also a single sprock-- et chain forengaging all the, sprockets atone side and a single sprocket chain forengagingv all the sprockets at the other side, and power means fordriving one set of sprockets, whereby the conveyor and apron advance atthe same rate of speed.

In testimony whereof I affix my signature;

' HENRY W. COOPER.

